Traffic stops of African American motorists in 2009 accounted for 12 percent of all Portland police traffic stops, a disproportionately high rate considering they make up about 6 percent of the city's population aged 16 and over.

Leslie Stevens, manager of the bureau's Office of Accountability and Professional Standards, presented both reports Wednesday night to the city's Community and Police Relations Committee.

Blacks have been stopped at more than twice the rate of white motorists when stop data from 2004 through June 2008 is analyzed, according to the report by PSU's Criminal Justice Policy Research Institute.

PSU's five-year study also compared data from daytime and nighttime traffic stops, and found there was a close to a 50 percent increase in traffic stops at night for all racial groups in Portland, with the percentage increase the largest for African Americans.

The study found that two-thirds of traffic stops of blacks occurred in 24 city neighborhoods that account for the very highest calls for police service and violent crime.

"It appears that citizen calls for service, neighborhood violent crime and proactive patrol are all interconnected with increased risks of African Americans being stopped in neighborhoods," the PSU study found. "Our conclusion does not imply that African Americans themselves are more likely to commit crimes given equal circumstances and should be treated with more suspicion."

Stevens, who will lose her job July 1 under the police chief's budget cuts, said the data historically has been compiled and released without informing management decisions.

"So the question is how do you manage the deliveries of that (police) service in a way that doesn't foster or contribute to a sense of distrust?" Stevens said.

Gang Enforcement Sgt. Tony Passadore, a committee member, said officers are trained to notice a person's "behavioral cues" when deciding whom to stop. If an officer makes contact with someone and then realizes "this isn't what I thought it was," Passadore says it's important the officer "turn it into a positive thing."

"The Police Bureau deploys its resources in areas where we have higher crime rates, where more minorities live," Passadore said. "That would explain part of the increase in numbers."

Dave Fidanque, executive director of Oregon's American Civil Liberties Union, said most residents in high-crime areas would welcome a greater police presence. If there are more minorities living in those areas, they're more likely to be seen by a police officer when they're committing a minor traffic offense, although there are patrol officers enforcing traffic laws throughout the city, he said.

"But they don't necessarily want to be stopped more often for failure to signal just because they live in that area," Fidanque said.

Further, he's concerned when young adults or teenagers who are not violating the law are stopped.

"You tend to push away the folks who should be your strongest allies."

According to PSU's five-year report, young male motorists stopped at night were more likely to be searched if in the East, Northeast or Southeast precinct boundaries or in a neighborhood that was economically disadvantaged.

The five-year report also found that the current data collected by the bureau doesn't sufficiently capture the factors that cause an officer to engage in a search.

The PSU researchers suggested the bureau collect more details on the reasons for stops, why police choose to conduct searches and provide ways to examine individual officers' stop histories.

"Being able to distinguish 'pretext-style' stops should be a key goal," the report says.

Chief Mike Reese, who had offered to patrol a North district neighborhood Wednesday night to give the officer of the month a night off, could not stay for the stop data discussion. But he urged the committee at the meeting's start to consider the bureau "a work in progress." He said he wants officers to think of themselves as public servants.